| 1. |
- Liu, Wei, et al.
(författare)
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Distribution of P75 neurotrophin receptor in adult human cochlea : an immunohistochemical study
- 2012
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Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 348:3, s. 407-415
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Tidskriftsartikel (refereegranskat)abstract
- Mechanisms underlying the unique survival property of human spiral neurons are yet to be explored. P75 (p75(NTR)) is a low affinity receptor for neurotrophins and is known to interact with Trk receptors to modulate ligand binding and signaling. Up-regulation of this receptor was found to be associated with apoptosis as well as with cell proliferation. Its distribution and injury-induced change in expression pattern in the cochlea have been mainly studied in rodents. There is still no report concerning p75(NTR) in post-natal human inner ear. We analyzed, for the first time, p75(NTR) expression in five freshly fixed human cochleae by using immunohistochemistry techniques, including myelin basic protein (MBP) as a myelin sheath marker and TrkB as the human spiral neuron marker, and by using thin optical sectioning of laser confocal microscopy. The inner ear specimens were obtained from adult patients who had normal pure tone thresholds before the surgical procedures, via a trans-cochlear approach for removal of giant posterior cranial fossa meningioma. The expression of p75(NTR) was investigated and localized in the glial cells, including Schwann cells and satellite glial cells in the Rosenthal canal, in the central nerve bundles within the modiolus, and in the osseous spiral lamina of the human cochleae. The biological significance of p75(NTR) in human cochlea is discussed.
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| 2. |
- Liu, Wei, et al.
(författare)
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Expression of peripherin in human cochlea
- 2010
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Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 342:3, s. 345-351
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Tidskriftsartikel (refereegranskat)abstract
- The organ of Corti contains two different types of auditory receptors; the inner (IHCs) and outer (OHCs) hair cells. This dualism is further represented in their innervation, IHCs being innervated by type I neurons, and OHCs by type II neurons (in man, named small ganglion cells). Two efferent systems are also present. Here, we have analyzed the expression of the 57-kDa neuron-specific intermediate filament protein peripherin (PP) in human cochlea. In the human organ of Corti, PP seems to be specifically expressed in OHC afferents. Small or type II spiral ganglion cell bodies also intensely express PP. Thus, PP can be used as a marker for the characterization of the innervation of the OHC system in man.
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| 3. |
- Liu, Wei, et al.
(författare)
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Expression of TrkB and BDNF in human cochlea : an immunohistochemical study
- 2011
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Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 345:2, s. 213-221
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Tidskriftsartikel (refereegranskat)abstract
- Surgical human cochlear specimens were obtained during the removal of large posterior cranial fossa meningioma by a transcochlear approach in which the cochlea was removed for maximal exposure of the tumor and protection of important structures, such as the brainstem, cranial nerves, and pivotal blood vessels. The cochlear tissue was fixed and cryo-sectioned for tyrosine kinase receptor B (TrkB) and brain-derived neurotrophic factor (BDNF) immunohistochemistry. TrkB receptor protein was expressed in both neuronal somata and the processes of human spiral ganglion neurons (SGNs). In the human organ of Corti, TrkB immunoreactivity was mainly present in nerve fibers underneath outer hair cells. BDNF expression was found neither in the organ of Corti nor in the spiral ganglion of human cochlea. For antibody specificity and for control and comparative purposes, TrkB immunocytochemistry was performed in primary cultures of cochlear neuron/glia from adult guinea pig. Confocal laser scanning microscopy showed that TrkB was homogeneously distributed in the cytoplasm of both neuronal somata and axons. Knowledge of the expression of TrkB receptor in human cochlea should help to determine the target structures for neuron preservation in hearing-impaired patients. Our results indicate that the regeneration of SGNs under pathological conditions can be enhanced with BDNF/TrkB-based pharmaceutical or genetic strategies.
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